UNITED WORE black at Highbury yesterday, a foolish colour in broiling heat but never more appropriate to their performance. Behind to first- half goals from Tony Adams and Nicolas Anelka they were reduced to shadows long before they were reduced to 10 men when Nicky Butt was sent off.

Butt's dismissal, for the second game in succession, came when he was harshly adjudged to have denied Patrick Vieira a goalscoring opportunity six minutes into the second-half. Though Butt followed former United players Mark Hughes and Eric Cantona in being sent off at Highbury this was not as spiteful as these matches have often been in recent years, United were never competitive enough for that. Their palsied performance fully deserved the final humiliation of a debut goal for Frederick Ljungberg, who must feel his reported low opinion of English footballers is ever more valid.

It was Arsenal's fourth successive victory over Manchester United inside a year at three different venues. The goal difference is 10-2 with Arsenal's defence undisturbed for five hours. Such dominance is unusual between championship contenders and there were clear signs that Arsenal have established a psychological edge over their unusually quiescent rivals.

With Vieira dominant, Marc Overmars a menace and the defence as resolute as ever Arsenal were even able to carry Dennis Bergkamp, who continues to search for a goal and his form. United are less capable of protecting Jaap Stam, who remains out of his depth. Not that defence was the only problem.

With Ryan Giggs curiously given a central striking role alongside Dwight Yorke they lacked midfield creativity, despite the untiring efforts of David Beckham, and attacking menace. They remain within the pack but Arsenal are now fifth, four points off early leaders Aston Villa.

It was about time one of these predators broke cover. Both have spent the early part of the season in the mid-table undergrowth, shaking off post-World Cup fatigue and allowing the likes of Villa, Charlton and Wimbledon to gambol in the high ground at the top. Now it was time to show their pedigree.

Arsenal were first to move, Bergkamp volleying over after Stam and Peter Schmeichel had got in a familiar tangle. United responded with a Beckham free-kick which David Seaman read well. It was a brief foray as Arsenal, better balanced in midfield and attack, took control. Stephen Hughes, an admirable replacement for the injured Emmanuel Petit, released Overmars for a cheeky shot which Schmeichel saved at his near post while even Lee Dixon got forward to test the Dane.

Then Jesper Blomqvist fouled Ray Parlour on the right. Hughes whipped the free-kick in and Adams, having lost his marker, Roy Keane, rose above Stam and ahead of Schmeichel to head in.

Bergkamp wasted two chances as Arsenal continued to dominate but then the champions had a moment of fortune. Beckham, given space 28 yards out, took possession and, while the boos were still forming in the Arsenal fans' throats, drilled in a shot which struck one post, rolled across the goal and into touch just wide of the other.

It was as close as United were to come. Arsenal resumed the assault and Parlour and Anelka both had chances before Stam, having made a fine tackle on Vieira, let Anelka escape onto Overmars' through ball. Schmeichel saved his first shot, but not the rebound.

Two-nil, and it got worse after the break as Butt, having been caught in possession, brought down Vieira on the edge of the box as he attempted to atone. Vieira was breaking clear but was wide of the goal with Stam coming up alongside. It looked a yellow card but Graham Barber, apparently believing it would take more than the presence of Stam to prevent it being a clear goal-scoring opportunity, pulled out the red. As Butt turned away in dismay Barber disappeared in a mass of dissenting black shirts. Schmeichel, alert to the danger of losing another team-mate, pulled them away one by one but not before Keane had talked his way into the book.

For all United's undoubted spirit that was game over. Arsenal do not throw away two-goal leads against 10 men and the insipid way United set about the task suggested they knew it. Even Alex Ferguson seemed unconcerned about a substitution, perhaps he felt that having played their way into this mess the remaining players should stay out there and suffer the consequences. For their part Arsenal kept their shape and patiently waited for the opportunity to rub in their superiority.

It ought to have come after 65 minutes but Anelka missed after Yorke had carelessly given the ball away to Bergkamp. Finally Ljungberg administered the coup de grace, chipping over Schmeichel after Hughes' chip forward had fallen to him. The sight of Stam and Schmeichel blaming each other in the wreckage of the United defence spoke volumes.